仅选择金额的第一部分

Question

假设我有下表（实际上这是查询的结果）

我想要的是提出下表

除了第一个代码值之外，它为每个代码值分配零。

任何策略都可以吗？

提前致谢

Answer 1

这有帮助吗？

declare @tab table(
       code int, 
       amount int)

insert into @tab values
    (1,100),
    (1,100),
    (1,100),
    (2,500),
    (2,500),
    (3,1000);

    select code, 
       case when rn=1 then 
           amount 
       else 0 end amount 
    from 
 (select *, 
          row_number()Over(partition by code Order by amount) RN 
      from @tab)t

Answer 2

您可以使用row_number()标识每个code的第一行。从那以后，它只是一个简单的case表达式：

SELECT code, CASE rn WHEN 1 THEN amount ELSE 0 END AS amount
FROM   (SELECT code, amount, 
               ROW_NUMBER() OVER (PARTITION BY code ORDER BY amount) AS rn
        FROM   my_table)

Answer 3

试试这个

SELECT Code,CASE When RN > 1 Then 0 Else Amount
FROM
(
   SELECT *,ROW_NUMBER() OVER (Partition by Code Order by (Select Null)) RN
   FROM Table1
) AS T

Answer 4

请尝试：

select Code, 
    case when ROW_NUMBER() over (partition by Code Order by Amount)=1 then Amount else 0 end Amount
From YourTable

Answer 5

请在下面的查询中用帐户更新表格：

SELECT A.code, 
       ( CASE 
          WHEN A.rno = 1 THEN B.amount 
          ELSE 0 
        END ) AS amount 
FROM   (SELECT Row_number() 
                OVER( 
                  partition BY code 
                  ORDER BY code DESC) AS rno, 
              code 
       FROM   account) AS A 
       LEFT OUTER JOIN (SELECT C.code, 
                               Sum(C.amount) AS amount 
                        FROM   account C 
                        GROUP  BY C.code) AS B 
                    ON B.code = A.code